An example of such a process of the present invention is the catalytic conversion of synthesis gas, comprising carbon monoxide and hydrogen, into middle distillates. In this process synthesis gas is supplied to the upper ends of the reactor tubes, passed through the reactor tubes and the effluents are collected downstream of the lower ends of the reactor tubes. To distribute the heat of reaction generated during the catalytic conversion uniformly over the cross-sections of the reactor tubes, and to improve heat-transfer from the interiors of the reactor tubes to the inner surfaces of the walls of said tubes a heat-transfer liquid is introduced into the upper ends of the reactor tubes. The heat of reaction is removed from the reactor tubes by a heat-transfer fluid which is passed along the outer surfaces of the said tubes.
In catalytic conversion processes use is made of multitube reactors having a diameter of about 5 m and comprising in the range of from about 5,000 reactor tubes with a diameter of about 45 mm to about 15,000 reactor tubes with a diameter of about 25 mm.
Such a large multitube reactor cannot be constructed in such a manner that it extends exactly vertically and small deviations from the vertical of about 1 cm per 800 cm are common.
It is an object of the present invention to provide a process for the catalytic conversion of a gas or a liquid in a multitube reactor having a plurality of substantially vertical reactor tubes wherein equal amounts of liquid are supplied to the reactor tubes to prevent overheating of one or more reactor tubes. British Pat. No. 976,036 discloses a reactor provided with a number of horizontal trays for liquid distribution, however, this patent does not relate to a multitube reactor as in the invention of this application.